Cassette deck of a car stereo

ABSTRACT

A cassette deck of a car stereo has at least one capstan and a motor for driving the capstan. An accessory switch is provided in a car provided with the car stereo. A accessory switch detector is provided for detecting closing of the accessory switch. A cassette detector is provided for detecting setting of a cassette to the cassette deck. In response to detection of closing of the accessory switch, and setting of the cassette, the motor is operated for rotating the capstan for a predetermined time.

BACKGROUND OF THE INVENTION

The present invention relates to a cassette deck provided in a carstereo, and more particularly to a cassette deck where a tape in thecassette is prevented from becoming entangled.

The cassette deck mounted in an automobile must be designed with regardto specific environmental conditions such as humidity, vibration anddust and to operability of the deck.

Referring to FIG. 7, in a cassette 1, a tape 2 wound on a hub is guidedby a guide pin 3a and a guide roller 4a and extends across a pressurepad 8. The tape 1 is further guided by a guide roller 4b and a guide pin3b and wound on a take-up hub. The cassette 1 is inserted in a cassettedeck in a direction shown by an arrow c, so that the tape 2 is setbetween a pinch roller 6b and a capstan 5a and between a pinch roller 6band a capstan 5b of the cassette deck. For playing the cassette 1, ahead 7 of the cassette deck is moved in a direction a so as to abut thetape 2 against the pressure pad 8. When thus playing the tape 2, or whenreeling the tape 2 in a direction shown by an arrow in FIG. 7, the pinchroller 6b is moved toward the capstan 5b to hold the tape therebetween.The tape is driven while thus in contact with the pinch roller 6b andthe capstan 5b both of which rotate with the running of the tape 2. Whenthe tape 2 is rewound, that is, reeled in the opposite direction, thetape 2 is held by the pinch roller 6a and the capstan 5a.

In order to retrieve the cassette 1, the head 7 is retracted in adirection b and the cassette is ejected in a direction d.

Some of the cassette decks are provided with a cassette deck detectingswitch which is closed upon insertion of the cassette. Thus the cassettedeck is operated to play the cassette as soon as the cassette is set.

While the cassette is played, the driver of the automobile may turn onother devices such as a CD player without first taking out the cassette,or the ignition switch is turned off thereby cutting off the power fromthe battery to the cassette deck. As a result, the cassette is leftinserted in the deck.

As shown in FIG. 8, a part of the tape 2 is held between the pinchroller 6b and the capstan 5b, or between the pinch roller 6a and thecapstan 5a as the case may be. If the cassette is kept in the cassettedeck for too long in such a condition, the tape 2 may adhere on thecontacting surface of the pinch roller 6b. Consequently, when thecassette 1 is driven the next time, the tape 2 may be wound on the pinchroller 6b, unabled to be reeled. The tape 2 may otherwise be torn.Moreover, the pinch roller 6b may be deformed by the pressure of thecapstan 5b, so that wow and flutter occur until the roller 6b retrievesits normal shape.

In order to prevent such troubles, a key-off release mechanism forretracting the pinch roller to its initial position is provided in sometypes of the cassette deck, hence preventing the tape from being stuck.However the manufacturing cost of the cassette deck is high.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a cassette deck wherethe tape can be reliably reeled without raising the manufacturing cost.

According to the present invention, there is provided a cassette deck ofa car stereo having a removable panel having a plurality of operationbuttons for operating the car stereo and attached to a body of the carstereo, the cassette deck having at least one capstan and a motor fordriving the capstan, comprising, an accessory switch detector fordetecting closing of an accessory switch of a car provided with the carstereo, a panel detector for detecting attachment of the removablepanel, a cassette detector for detecting setting of a cassette to thecar stereo.

Control means is provided to respond to detection of closing of theaccessory switch, attachment of the removable panel, and setting of thecassette for operating the motor for rotating the capstan for apredetermined time.

In another aspect of the present invention, there is provided a cassettedeck of a car stereo, the cassette deck having at least one capstan anda motor for driving the capstan, comprising, an accessory switchdetector for detecting closing of an accessory switch of a car providedwith the car stereo, a cassette detector for detecting setting of acassette to the car stereo.

Control means is provided to respond to detection of closing of theaccessory switch, and setting of the cassette for operating the motorfor rotating the capstan for a predetermined time.

The other objects and features of this invention will become understoodfrom the following description with reference to the accompanyingdrawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1a is a perspective view of a car stereo to which the presentinvention is applied;

FIG. 1b is a diagram showing a circuitry of a cassette deck of thepresent invention for controlling the operation of the cassette;

FIG. 2 is a perspective view of a pinch roller and a capstan of thecassette for explaining the operation thereof;

FIG. 3 is a block diagram of a microcomputer provided in the circuitryof FIG. 1b;

FIG. 4 is a flowchart showing the operation of the cassette deck of thepresent invention;

FIGS. 5 and 6 are flowcharts showing modifications of the operation ofFIG. 4;

FIG. 7 is a plan view of a cassette set in a conventional cassette deck;and

FIG. 8 is an enlarged plan view of a pinch roller and a capstan of theFIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is applied to a cassette deck of a car stereomounted in an automobile, and having a similar constructions as thatshown in FIG. 7.

Referring to FIG. 1a showing a car stereo, the car stereo comprises acar stereo body 30 and a removable panel 31 attached to the body 30. Thebody 30 has recessed panel 32 mounted at the front thereof. The panel 32has a cassette opening 33. A panel detector switch 34 is provided on thepanel 32 to detect the attachment of the panel 31 on the body 30. Thepanel 31 has a cassette opening 35 which coincides with the cassetteopening 33 of the body 30 and various operation keys 36. A display 37 isdisposed on the panel 31 so as to indicate information such as currenttime and the received frequency of the stereo.

Referring to FIG. 1b, a control system according to the presentinvention comprises an accessory switch 10 which is closed when anignition key of the automobile is at an accessory position. In anautomobile without an accessory switch, the ignition key thereof isused, instead of the accessory switch. The accessory switch 10 isconnected to a base of a transistor Q1 thorough a voltage regulationdiode 11. The collector of the transistor Q1 is connected to amicrocomputer 12 supplied with power V_(DD) at an accessory switchsensing port m. The panel detector switch 34 is connected to themicrocomputer 12 through a panel sensing port n. The microcomputer 12further has a cassette sensing port o which is connected to a cassettedetector switch 15. The cassette detector switch 15 is closed when thecassette is set in the cassette deck at the position shown in FIG. 7.

An output port p of the microcomputer 12 is connected to a motor 14 fordriving the capstans 5a and 5b shown in FIG. 7 through a driver 13.

Referring to FIG. 3 showing the microcomputer 12 in detail, themicrocomputer 12 is applied with a signal from a mode key 20 mounted onthe panel and operated when selecting one of the devices of the carstereo, such as the cassette deck and CD player. The signal is appliedto a mode detector 21 where the selected mode is determined. Thedetermined mode is stored in a memory 22 so that when the accessoryswitch 10 is opened and again closed after some time, the car stereoautomatically resumes its operating mode stored in the memory 22.

The output signal of the mode detector 21 is further fed to a controller26 which controls the operation of the driver 13 of the cassette deckand the operation of other devices. The controller 26 is further fedwith signals from an accessory switch detector 23, cassette detector 24and panel detector 25 which are connected to the accessory switch 10,cassette detector switch 15 and the panel detector switch 34 shown inFIG. 1b, respectively. Namely, when the accessory switch 10, cassettedetector switch 15 and the panel detector switch 34 are closed, thelevels at the corresponding ports of the microcomputer 12, that is, eachof the accessory switch sensing port m, cassette sensing port o and thepanel sensing port n becomes low. The controller 26 operates the driver13 and other devices in the car stereo in accordance with the conditionsof the switches 10, 15 and 34. If the cassette detector switch 15 isclosed, the reproduction of the tape is performed.

The controller 26 further operates a timer 27 to set a predeterminedperiod of time T for actuating the driver 13. When the cassette deck isin such a state that the accessory switch 10 or an ignition key has beenopened while the cassette is left in the cassette deck, the controller26 operates the driver 13 to drive the motor 14 for the period of time Tat the re-closing of the accessory switch 10.

The operation of the cassette deck is described hereinafter withreference to FIG. 4.

When a cassette is left in the cassette deck, the cassette detector 24detects the closing of the cassette switch 15. When the operating panelis attached to the car stereo so as to be able to operate the carstereo, the panel detector 25 detects the closing of the panel detectorswitch 34. Under such a condition, when the ignition key is turned on sothat the accessory switch detector 23 detects that the accessory switch10 is closed, the program proceeds through steps 401 to 403 and to astep 404 where the timer 27 is set to a predetermined time T, forexample 100 msec. Accordingly, the controller 26 of the microcomputer 12applies a control current to the driver 13, thereby to drive the motor14 for the time T. As a result, the capstan 5b is rotated one fourth ofa rotation at a step 405. As shown in FIG. 2, a portion of the tape 2indicated by hatchings which had been in contact with the pinch roller6b and hence liable to adhere on the roller 6b advances a predetermineddistance so as to be released from the pinch roller 6b. After the time Tis elapsed (step 406), the motor 14 is stopped at a step 407.

As shown in FIG. 5, the operation may be modified to determine at a step501 that the accessory switch 10 is closed, and at a step 502 that thecassette switch 15 is closed before driving the motor 14 for the time T.Namely, the attaching of the panel is not considered. Steps 503 to 506are the same as the steps 404 to 407 in FIG. 4.

FIG. 6 shows another modification where the attaching of the panel (step601) when the cassette is inside the cassette deck (step 602) is theprerequisite for driving the motor 14 for the time T. Steps 603 to 606are the same as the steps 404 to 407 in FIG. 4.

The period of time T for driving the motor 13 need not be limited to 100msec as long as the adhering portion of the tape 2 is displaced from thesurface of the pinch roller and hence may be shorter or longer than 100msec.

Thus, although the power to the cassette deck is cut off so that thecassette is left inside the deck, upon closing of the accessory switchor the attachment of the removable panel of the cassette deck, the tapeis advanced a small distance. Hence the tape is prevented from adheringon the pinch roller so that the tangling up or the tear of the tape isavoided the next time the tape is reeled. Furthermore, the pinch rolleris prevented from temporarily deforming by the pressure of the capstan,so that the wow and flutter which are liable to occur until the pinchroller resumes its normal shape are prevented. Since the presentinvention involves only a simple mechanism, the object is attainedwithout increasing the manufacturing cost.

While the presently preferred embodiments of the present invention havebeen shown and described, it is to be understood that these disclosuresare for the purpose of illustration and that various changes andmodifications may be made without departing from the scope of theinvention as set forth in the appended claims.

What is claimed is:
 1. A cassette deck of a car stereo having aremovable panel having a plurality of operation buttons for operatingthe car stereo and attached to a body of the car stereo, the cassettedeck having at least one capstan and a motor for driving the capstan,comprising:an accessory switch detector for detecting closing of anaccessory switch of a car provided with the car stereo; a panel detectorfor detecting attachment of the removable panel; a cassette detector fordetecting setting of a cassette to the cassette deck; driving controlmeans responsive to detection of closing of the accessory switch,attachment of the removable panel, and setting of the cassette foroperating the motor for rotating the capstan for a predetermined time.2. A cassette deck of a car stereo, the cassette deck having at leastone capstan and a motor for driving the capstan, comprising:an accessoryswitch detector for detecting closing of an accessory switch of a carprovided with the car stereo; a cassette detector for detecting settingof a cassette to the cassette deck; driving control means responsive todetection of closing of the accessory switch, and setting of thecassette for operating the motor for rotating the capstan for apredetermined time.
 3. A cassette deck of a car stereo having aremovable panel having a plurality of operation buttons for operatingthe car stereo and attached to a body of the car stereo, the cassettedeck having at least one capstan and a motor for driving the capstan,comprising:a panel detector for detecting attachment of the removablepanel; a cassette detector for detecting setting of a cassette to thecar stereo; driving control means responsive to detection of attachmentof the removable panel, and setting of the cassette for operating themotor for rotating the capstan for a predetermined time.
 4. A cassettedeck according to claim 2 wherein a timer is provided for setting thepredetermined time.